This invention relates to an escape device for escaping from a multi-stored building or other high areas in an emergency comprising a worm gear mechanism driven by an electric motor, operatively coupled to a reel having a length of high tensile line wound around it, a casing enclosing operative components, and a belt connected to the casing for supporting a person's body.
In a previously known escape device, a speed reduction means such as a gear mechanism is mounted on a frame member which is attached to the exterior of a building with a thick rope connected to the gear mechanism, That device is expensive, heavy, and not easily portable. The escape height is limited due to the thickness of the rope.
Japanese Patent Publication No 63-137370 discloses an escape device having a braking means including brake shoes, wedge members and handle levers operatively connected to a reel means having a long high tensile string attached, and having a belt member for supporting a person's body. In that invention, the descending person adjusts the braking force by operating the handle levers, which cause the wedge members and brake shoes to frictionally contact the string to reduce the descending speed. The braking force is unstable due to differences in body weight of descending persons and due to varying friction characteristics of the brake shoes. It is also difficult to operate the handle levers while descending. That invention presents problems with quality control and safety control.
In another previously known escape device, a rope of about 5.0 mm in diameter is used with speed reduction means utilizing the viscosity of silicon oil. That invention has an unstable braking force due to variations in the viscosity of the silicon oil. The escape height of that invention is limited due to the thick rope used. It is also large, heavy, and expensive.
The object of the present invention is to provide an escape device which has an easily controlled descending speed and which is portable and economical.
This object has been achieved according to the present invention by providing an escape device comprising a worm gear mechanism driven by an electric motor, operatively coupled to a reel, with a line wound around the reel. These components are contained within a casing which has a belt means attached to support a person's body. In the case of an emergency in which one needs to escape from a building, the user attached himself to the escape device by using the belt means. Then the user attached the end of the line, which may have a hook connected to it, to a fixture of the building, such as a door knob, window frame, bed or other furniture, faucet, etc. The user then may climb out of a window or other opening and lower himself to the ground or a safe place below by operating the escape device. The user grasps the escape device by placing each hand through hand holes in the casing. The user controls his descent by operating a main switch on the exterior of the casing which operates the electric motor. The electric motor turns the worm gear mechanism which turns the reel, feeding the line out form the reel and thereby lowering the user toward the ground or a safe place below. The line is attached to the reel, and the worm gear mechanism has a locking function, so that in the case of the line length being less than the escape height, the user will not drop off the lend of the line. Although the present invention is primarily intended for use by people, it may also be used or adapted to lower pets or valuables from a high area in an emergency.
Any line length may be used, for example, 10.about.300 meters. The line is preferably a high tensile steel such as piano wire, or a high tensile plastic material such as carbon fiber. The line preferably has a tensile strength, .sigma..gtoreq.100 kgf/mm.sup.2, and more preferably, .sigma..gtoreq.150 kgf/mm.sup.2. The tensile strength, F, of the line, must be greater than the user's body weight, The diameter or section area of the line is selected based on .sigma. and F. The line may be a single strand or multiple strands.
The electric motor and in turn the worm gear mechanism rotate at a constant speed, so users of varying weights descend at the same speed, for example, 1.0-3.0 meters/second. The diameter of the wound line decreases as the line is fed out from the reel, resulting in a decreasing descending speed as more line is fed out from the reel, This has the benefit of slowing the rate of descent as the user nears the ground. To obtain a constant descending speed, or to vary the descending speed, an electric motor with a variable output may be used. The electric motor preferably is reversible so that in the case that too much line is fed out, the electric motor can be reversed to tighten up the slack by winding the excess line around the reel, The electric motor is preferably driven by direct current from a battery.
In one preferred embodiment of the present invention, the escape device is constructed in a compact and lightweight manner so that it is portable, so that it may be easily carried by travelers in their luggage, stored by office workers in their desks, or stored by a hotel in each of the rooms. In this regard, a worm gear mechanism which has a large speed reduction ratio is used, requiring a less powerful electric motor, thereby allowing the electric motor and battery to be smaller. A line having a high tensile strength is used to reduce the size and weight of the device.
In another embodiment of the present invention, the escape device may be constructed in a heavy duty manner, using heavier and bulkier materials and components, This embodiment may be applicable for permanent mounting to a building such as a hotel. In this embodiment, the reel may be enlarged to be a drum, so that the line can be substantially lengthened.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.